Thermally-operated means for automatically disrupting electric alarm-circuits, &amp;c.



H. S. TURNER.

THERMALLY OPERATED MEANS FOR AUTOMAICALLY DISRUPTNG ELECTRIC ALARMCIRCUlTS, &c. APPLICATION FILED SEPT. 18. !914.

1 1 7 l ,5 64 Pateted Feb. 15, 1916.

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` wucntoz ncooeo 4 %khan Diego, in the county T EmLLY-ormmrm HEARS ronUNITED STA'EES PATENT OFFICE;

HUBEBT S. TURNEB, OF SAITDIEG, CALIFOBNA.

To all whom it may concem:

Be it'known that I, HUBERT S. TURNER, a' citizen of the United States,residing at San of San Diego and State of (Jalifornia, have inventedcertain new and useful Improvements in Thermally-Operated Means forAutomatical'ly- Dsrupting Electric Alarm-Circuits, &c., of which thefollowing is a specificaton.

alarm circuits are only broken temperature,

said strand and cause the continuity stitute for the This invention hasfor its principal object the elimination of .special thermostaticdevices inserted at intervals in electrical alarm oircuits, for thereason that such' eleetric when one of said devices is directly aflectedby a hi h and if said device shou d located at some distance from saidhigh temperature (as is often the case in practice) it does not operateuntil the area of high temperature has spread sufhappen to be 'ficientlyto directly aifect it. 'Iaccomplish this object by means of anelectrically continuous strip or strand, formed of comparatively shortsections of a metal of preferably low heat conductivity and connectedtogether at their ends by means of a fusble alloy having a preferablylow melting point. This continuous strand is fastened to the walls,-ceilings or other convenient portions of the premises protected by anelectric alarm circuit controlled by such a strand, the location of thesame being such that a high .temperature developed at any given pointwill soften the fusible alloy at the nearest connecting point of saidsections of of the same to be broken, thus Operating the alarm. In thismanner, not only does every connecting point of said sections act as asubspecial thermostatic devices usually nserted at intervals in anelectric alarm circuit, but the strand as a whole acts as a substitutefor the wire o'dinarily used to connect said devices. The cost ofinstalling said strand is also less than the cost of installing saidwire and thermostatic devices. It will be understood, however, that ifdesired, thermostatic circuit breakers of any known type may be insertedin the circuit formed by said strand.

The strand of my invention provides a new and useful device that isadapted to be arranged or included in any suitable fire' speemcatlon otLetters Patent.

AUTOMATICALLY DISBUPTING' ELECTBIC ALARM- CIBBUITS, dac.

` 'atented Feb. 15, 1916.

u Application filed September 18, 1914. Serial No. 862337..

alarm circuit that will provide for giving an alarm-when the same isbroken, and to this end the present invention contemplates a strand thatprovides for a normally closed circuit and which while extremely simple,nexpensive and easy to install, at the same time is suflicientlysensitive to heat as to provide for quickly opening the circuit andgiving an alarm when sub ected to a high temperature which may developin the vicinity of any part of said strand.

,With these and other objects in View which will readily appear as thenature of the invention is better understood, the same consists in thenovel Construction, combination and arrangement of parts hereinafterfully described, illustrated and claimed.

This strand is preferably extremely narrow and thin, its width andthickness depending on the location where it is to be used and the risksof mechanical injury to which it may be subject. For purposes ofclearness, in the drawing the longitudinal views purposely show 'anexaggerated thickness of the sections of said strand. The

sections are also shownextremely short for in the protected premises.

In the accompanying drawing, Figure 1 is a plan View of a portion of astrand constructed in accordance withthis invention; Fig. 2, alongitudinal view of the same showing the strand as normally positionedto close the. electrical circuit, and as installed on a wall orpartition; Fig. 3, a similar vew showing one section of the strandreleased at one end from the section with which it is normally engaged,when the fusble alloy which connected them has been softened by heat;"and Figs. 4 and 5, alternative forms of said strand.

Referring to the accompanying drawngs, 1 designates sections of saidstrand, which overlap at their ends a short distance as shown where theyare joined together by said fusible alloy 2 as indcated by means of I isaid fusihle alloy are .what I designate heat conducting antennae,consistingof a plurality of fine wires or strips of metal 3 of apreferably high heat conductivity and of a length varying according tothe location of said strand .and the degree of operating sensitivenessdesired. Preferably, said antennae are placed at their Centers betweenthe ends of said sections when the latter are joined together by meansof said fusible alloy .and therefore the center of said antennae areembedded in said fusible alloy. a The ends of said antennae arepreferably otherwise he if no such antennae were used, t as the heatedar from' a large area s thus led to act on said fusible alloy, insteadof the same being acted upon solely by the heated air which might comein contact with the connected ends of the sections alone. The softeningof the fusible alloy is materially hastened if the sections of thestrand are made of a metal of low heat conductivity, such as Zinc or,brass and the antennae made of a metal of high heat conductivity, suchas copper, as in this case the heat absorbed from the air by theantennae is concentrated in the fusible alloy and is not dissipated moreor less throughout the length of the section, as would be the case ifthe sections were composed of a metal of a high heat `conductivity.However, I do not wish to be limited to such combination of metals.While I have shown in the drawings seven wires or strips comprising theantennze, it will be understood that I do not limit myself to anyparticular number.

No special mounting 'for the strand is shown as the same'is intended tobe mounted directly on the walls, ceilings, partitions or otherconvenient portions of the protected premises. However, in attachingsaid strip in damp places or where it crosses other electric conductors,pipes or metallic ohjects which might short-circuit 'a section of thestrand, an nsulatng hacking of any desired form can be used, or ifpreferred, an insulating hacking can be used for the full length of thestrand.

In fastening the strand to its sustaining means, it may he bentoutwardly .in such a manner that the elasticity or springiness of themetal will cause the overlapping end of a section to ring away from thesection to which it is fastened, when heat 'has softened the fusiblealloy used for connecting said sections. By utilizing this elasticity orspringiness of the sections, the continuity of the strand is broken muchquicker than it would otherwise be, as the fusihle alloy will not needto he softened so much before the mechanical strain, caused by saidelasticity ordspringiness, will separate the connected en s.

In Fig. 3 I have shown the appearance of a portion of the strand whenone of the overlapping ends of a section of the same has beendisconnected from the section to which it was joined, by means of thesoftening of the fusible alloy used' to connect them. A part of theantennae may remain attached to the end of one section and a part to theend of the other section, as shown in the drawing (Fig. 3), or a part orall may be entirely detached from either or both ends, according tocircumstances. i In Figs. 2 and 3 I have also shown a preferred mannerofattaching the strand to its sustaining means; the sections, the endsof which outwardly overlap -the ends of the other sections, being leftentirely free from any attachment to the sustaining means, while theunderlying sections are each at- .tached thereto by means of staples,--as shown at 4, or in any other convenient manner. While I have shown inthe drawing but one such fastener for each section attached to thesustaining means, it will he understood that more may be used if thelength of the sections requires it. This preferred form of attaching thestrand is purely a precautionary measure to avoid thepossibility of theelasticity or springiness ofan overlapping section not being suflicientto free its end when the softeuing of the fusible alloy takes place; asshould this happen, as soon as 'the fusible alloy at the other end ofsaidoverlapping section is softened, gravity would cause the entiresection to fall, thereby breaking the continuity of said strand andopening the electrical alarm circuit controlled hy it. On this accountthe strand is also preferahly mounted in such a manner that gravity willalways act on said overlapping sections when the fusible alloyconnecting their ends is sufiiciently softened However, it will be foundin practice that if properly installed, the elasticity or i springinessof the sections can be relied upon .overlapping spring section of saidstrand so that when the ends of the adjacent undermeans as shown at 6,said overlapping spring lying sections are fastened to thesupportingsection is out'wardly bowed, producng a v mechsnical strain atthe ends of the same,

which assures the prom'pt disconnection of i the ends when the fusiblealloy which con-= nects them to the underlying sections is softened. Thedotted lines in Fig. 4 show the form assumed by said section when thefusible alloy is softened. At 7 and 8, Fig. 4, is shown how mechanicalsupports may be substituted for said projecting stud. It will also beunderstood that one of such studs or supports may be used near each endof an overlapping section, if the same are so long that one such wouldnot be suflicient -to obtain the desired mechanical strain at the endsof said section.

Fig. 5 is a longitudinal view showing a modified way of overlapping theends of the sections of the strand, wherein one end of each sectionoverlaps and one end underlies' adjacent sections. A preferred manner ofattaching the strand to its sustainingmeans is shown at 9, one sectionbeing left free from fasteners between the fastened sections, thusallowing gravity to assist in breaking the continuity of the strand, ashereinbefore described in relation to the other forms of the strand. v

While in each figure I have shown the heat conducting antennae 2, itshould be I understood said antennae may or may not be used as desiredand I do not limit my invention, in all of its aspects, to the use ofsaid antennac.

From the above it will be seen that the strand of my invention, whilevery simple in form, is extremely sensitive in operation and that thereare no parts capable of being afi'ected by dust or dirt and no specialdevices to install, inspect and maintain.

Changes in form, proportion and minor details of Construction, otherthan those mentioned, may be resorted to without departing from theprinciples involved or savificing any of the advantages of thisinvention.

The' combination of metallic members joined together by means of afusible alloy or binding means having a lower fusing point than saidmembers and heat conducting antennae as described and shown in thedrawings, is claimed broadly as such combination is adaptable toincrease the sensitiveness in operation of any means relying'on heat tosoften or melt said fusible alloy or binding means. It should also beunderstood that while I have herein used the expression fusible alloy todescribe the highly fusible binding medium, joining the conductorsections of the strand together, any suitable alloy, metal or fusiblemetallic binding agent may be employed within the scope of my inventionas herein claimed.

Having thus described my invention, I claim as new, and desire to secureby Letters Patent the following:-

1. Thermally operated means, comprising metallic members joined togetherby binding means having a lower fusing point than said members, ncombinaton with metallc heat conducting antennae extending into saidbinding means and adapted to conduct heat thereto from the surroundingmedium.

2. Thermally operated means, comprising metallic members of low heatconductivity joined together by binding means having a lower fusingpoint than said members, in combinaton with metallic heat conductingantennae of high'heat conductivity extendingtrically continuous strandformed of spring e metal sections joined together at their ends bymetallic binding means having a lower fusing point than said sections,projecting studs formed in sections of said strand to outwardly bow suchsections when said strand is attached to supporting means, said sectionsoutwardly bowed serving to break the electrical continuity of saidstrand when said binding means is softened.

5. A thermostatic conducting strand 'or electrical alarm circuits,comprising an electrically continuous strand formed of metal sectionsjoined together at their ends by binding means having a lower fusingpoint than said sections, in combination with metallic heat conductingantennae extending lCO into said binding means and adapted to coni ductheat, thereto from the surrounding medium.

6. A thermostatic conducting strand for electrical alarm circuits,comprising an electrically continuous strand formed of metal sections oflow heat conductivity joined together at their ends by metallic bindingmeans having a lower fusing point than said sections, in combinationwith metallic antennae of high heat conductivity extending into saidbinding means and adapted to conduct heat thereto from the surroundingmedium.

7. A thermostatic conducting strand for electrical alarm circuits,comprising an electrically continuous strand formed of spring metal'sections joined together at their ends by a binding means having a lowerfusing point than said sections, supports to outbination with metallicheat conducting antennae extending into said binding means and adaptedto conduct heat thereto from the surrounding medium.

8. A thermostatic conducting strand for electrical alarm circuits,comprsing an electrically continuous strand formed of spring metalsections of low heat conductivity joined together at their ends by'metallic binding means having a lower fusing point than said sections,supports to outwardly bow sections of said strand when it is attached tosupporting means, in combination With metallic antennae of high heatconductivity extending into said binding means and adapted to conductheat thereto from the surrounding medium.

9. A thermostatic conducting strand for electrical alarm circuits,comprlsing an electrically continuous strand formed of spring metalsections joined together at their ends by a binding means having a lowerfusing point than said sections, projecting studs formed in sections ofsaid strand to outwardly boW such sections When said strand is attachedto supporting means, in combinetion with metallic heat conductingantennae extending into said binding means and adapted to conduct heatthereto from the surrounding medium.

10. A thermostatic conducting strand for electrical alarm crcuits,comprsing an electrcally continuous strand formed of spring my name this18th day of September A. D., 1914. HUBERT S. .TURNER. Witnesses:

E. G. MARSHALL, G. M. COPENHAVER.

heat conductivity ex-

